virtio_blk: implement mq_ops->commit_rqs() hook

We need this for blk-mq to kick things into gear, if we told it that
we had more IO coming, but then failed to deliver on that promise.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 6e869d0..912c426 100644 (file)
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -214,6 +214,20 @@ static void virtblk_done(struct virtqueue *vq)
        spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
 }
 
+static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx)
+{
+       struct virtio_blk *vblk = hctx->queue->queuedata;
+       struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
+       bool kick;
+
+       spin_lock_irq(&vq->lock);
+       kick = virtqueue_kick_prepare(vq->vq);
+       spin_unlock_irq(&vq->lock);
+
+       if (kick)
+               virtqueue_notify(vq->vq);
+}
+
 static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
                           const struct blk_mq_queue_data *bd)
 {
@@ -638,6 +652,7 @@ static void virtblk_initialize_rq(struct request *req)
 
 static const struct blk_mq_ops virtio_mq_ops = {
        .queue_rq       = virtio_queue_rq,
+       .commit_rqs     = virtio_commit_rqs,
        .complete       = virtblk_request_done,
        .init_request   = virtblk_init_request,
 #ifdef CONFIG_VIRTIO_BLK_SCSI